Is it Too Hot to Work Your Horse?

The first break from chores is scheduled for 5:20 every morning. It's time to watch the weather report and catch the two momentary comments that will determine the day's schedule: What will the temperature and the relative humidity be for the day. It the environmental heat stress index (EHSI) is going to be over 140 the horses get the day off from heavier work. They still may need to learn or practice something for the day, such as how nice a cooling hose down feels, but the will have the day off from "human induced" sweating.

The EHSI is determined by adding the days temperature to the relative humidity. Fro example, if the weather forecaster says humidity is 67% and temperature is 85, the day's EHSI is 152. An EHSI of over 140 indicates the need for increased caution when working horses. Relative humidity is a significant factor because it inhibits the evaporation of sweat. Sweating is the primary cooling mechanism for the horse, so on days when the EHSI is over 140, early morning or late evening workouts may be the best schedule for the health of your horse.

Another note to consider is that moving air takes up moisture as it moves across a surface. (Remember this from 6th grade science!) Air moving across a horse's body increases evaporation, thus helping to cool the horse. For this reason, adequate ventilation, especially in the summer, is extremely important to horses. Installing fans will help circulate air in your barn, and a nice breeze outside will help cool your horse while working, canceling some of the negative affect of a high EHSI.

Other factors contributing to how well a working horse handles heat are determined by how much water the horse consumes, access to balanced salt and rations, and your horses overall condition. With hard work and temperatures in the 70's a 1,500 pound adult horse will easily consume 30-35 gallons of fresh water a day; compared to a minimum of 15-25 gallons for an idle horse of the same size. Just like humans, horses conditioned to work many hours a day, who also have access to adequate amounts of salt, water and rations, will handle hot weather better than those that don't.

Although using the hottest days as your horse's scheduled "days off" as much as possible is a good idea, the hot weather and high EHSI days need not interrupt your horses training. If a scheduled training falls on a high EHSI day we'll use the session for light work and a chance to revisit the basics. For young horses in driving training this might be basic groundwork to refresh gee, haw, whoa and back, of maybe a walk through a new obstacle pattern. Practicing for halter classes and standing square and alert "no matter how bored you are" might be another lesson.

The hotter days are also a good opportunity to desensitize horses to loud and unusual noises, or strange items they might encounter someday. Learning today that an umbrella won't kill them might be remembered when they see one at a windy, rainy horseshow! If a horse isn't too keen on baths, this is a perfect time to teach them how refreshing water can be. They can learn to stand still with a hose moving near their feet or with the sound of high-pressure water hitting a wall near them. Hotter days can also be used to practice clipping or the latest braiding techniques. Working on a few things you and your horse need improvement on during the lazy hazy days of summer will pay off in the long run. Though the hours of work under saddle or in harness are outwardly rewarding to judges and crowds, it's a well-behaved horse in any situation that owners find most enjoyable.

Vicki Schmidt owns and operates Troika Drafts in Hebron, Maine.

The farm includes The Shoeing Shop, featuring the farrier work of Frank Walker.